Question: What physical theory starts with the letter "t"?
Paraphrase: What physical hypothesis begins with the letter "t"?
SPARQL (Wikidata): SELECT DISTINCT ?sbj ?sbj_label WHERE { ?sbj wdt:P31 wd:Q9357058 . ?sbj rdfs:label ?sbj_label . FILTER(STRSTARTS(lcase(?sbj_label), 't')) . FILTER (lang(?sbj_label) = 'en') } LIMIT 25 
Answer: Tensor–vector–scalar gravity, Tensor–vector–scalar gravity, theory of everything, theory of everything